In many processes, a product that is to be milled is held in a wet suspension in a preliminary process (precipitation, flotation, washing). If the milled end product exists in dry form, the desired final moisture content is to be selected in a complex process, such as through mechanical pre-dewatering, for instance in filter presses, and then thermal drying. Milling to a required final degree of fineness, finally, is performed frequently in jet mills. Typical applications are, for example, the production of talcum, silicic acid, magnesium hydroxide or ceramic ink-jet pigments.
The disadvantage here is the total expenditure in equipment and time in order to obtain a millable product from a wet suspension eventually with a desired final moisture content and final degree of fineness.